The present invention relates generally to micronutrient supplements for food or animal feeds that enhance the survivability, growth, health and/or reproductivity of humans and other animals. More specifically, the present invention is directed to method of producing a basic salt of an essential metal, which provides high bioavailability of the essential metal to humans and other animals. In particular the present application provides a method of producing micronutrients in the form of basic metal salts that uses copper metal as a starting material.
Nutrients include vitamins and some elements usually in the form of minerals or metal salts; most notably the elements include calcium, phosphorus, potassium, iron, zinc, copper, magnesium, manganese and iodine. Micronutrients are generally consumed in small amounts, i.e., less than 1 gm/day, and many essential elements have catalytic functions. While the micronutrients are often present in minute amounts, their bioavailability is essential for survival, growth, health and reproduction. Micronutrients are important for children and other young animals, particularly during their early development years when they are rapidly growing. Furthermore, many new animal breeds require additional amounts of micronutrients as their abilities to grow at a faster rate while consuming less feed has improved. This intensive growth imposes greater metabolic stresses, causing increased susceptibility to vitamin deficiencies. It is well recognized that the needed micronutrients are often not found or not found in sufficient quantities in their food or feed sources, whether these sources are naturally occurring or commercially prepared. Consequently, virtually all industrial food and feed formulations are fortified with vitamins and minerals. The cost to commercial livestock producers for supplying micronutrients to their livestock herds can be staggering.
While human and animals' needs for additional nutrients have been well documented, the availability of the micronutrients has not always met their needs. It is not sufficient to simply increase amounts of the micronutrients in the food or feed sources. This method is ineffective, wasteful and unsafe. Many of the micronutrients are not readily absorbed; the added amounts of vitamins and minerals are simply excreted without being absorbed. Excess loading of vitamins and minerals is unsafe, and in certain circumstances, excess loading can be toxic, causing severe acute and chronic harm and can even be fatal. Thus, there is a need to provide an inexpensive, readily absorbed micronutrient to decrease costs, reduce waste and to help establish a more precise control of the nutritional requirement for humans and animals.
There is a need to provide a micronutrient supplement that is readily bioavailable, storage stable and compatible with a wide variety of different vitamins. The micronutrient supplement must also be cost-efficient to produce and provide a food source for humans and animals that will increase their survivability, growth, health and/or reproductivity.
Micronutrients are commonly produced and available in the form of salts, oxides and complexes. Oxides are relatively inexpensive; however, they are not as effectively absorbed as salts and chelated forms of micronutrients.
Complexes and particularly well-defined chelated micronutrients are relatively expensive; however, they are more easily absorbed and have good bioavailability.
Examples of various micronutrients can be found in U.S. Pat. Nos. 4,021,569, 3,941,818, 5,583,243 all to Abdel-Monem, U.S. Pat. No. 4,103,003 to Ashmead, U.S. Pat. No. 4,546,195 to Helbig et al., U.S. Pat. Nos. 4,900,561, 4,948,594 both to Abdel-Monem et al. U.S. Pat. No. 5,061,815 to Leu, U.S. Pat. No. 5,278,329 to Anderson, U.S. Pat. No. 5,698,724 to Anderson et al. U.S. Pat. No. 6,114,379 to Wheelwright et al. U.S. Pat. No. 7,523,563 to Hopf and U.S. Patent Application Publication No. 2010/0222219 to Lohmann et al.
At least one of the present inventors is a co-inventor of U.S. Pat. Nos. 5,534,043, 5,451,414 and 6,265,438, and U.S. Patent Application Publication No. 2013/0064963. These patents and published patent application disclose micronutrients that are basic metal salt of the formula M(OH)yX(2−y)/i, and its hydrate forms, where M is metal cation, X is an anion or anionic group, and i is 1-3 depending on the valence of X.
The micronutrients disclosed in U.S. Pat. Nos. 5,534,043, 5,451,414 and 6,265,438 were originally developed from a process that used spend etchant solutions as a source of the metal cations and a crystallization process to produce a basic metal salt having a particle size of about 30 to 300 microns.
U.S. Patent Application Publication No. 2013/0064963 describes micronutrients in the form of basic metal salts that have more versatility than similar micronutrients and which have a high degree of bioavailability and which are produced by reacting a metal oxide, or metal hydroxide, or metal carbonate of an essential mineral and an acid to form a slurry with a digestible binder and forming agglomerated particles by spray drying or other means of agglomeration.
The present application provides a method of producing micronutrients in the form of basic metal salts that uses copper metal as a starting material.
Prior to the present invention at least one co-inventor of the present invention were interested in finding better ways to make essential trace minerals to be used as nutritional supplements. They discovered that a compound's chemical structure would dictate its reactivity (rate of undergoing chemical/biochemical reactions), so they initially turned their attention to the development of a manufacturing process that would consistently produce a particular crystalline structure. Eventually they developed and refined a process to produce a unique crystalline compound that is a combination of the minerals atacamite and clinoatacamite.
Later numerous animal feeding trials were conducted and it was unexpectedly discovered that the tested essential trace minerals demonstrated significant advantages over traditional copper compounds used in nutrition. U.S. Pat. No. 5,451,414 (cited above) is directed to the discovered improved way to supply copper, a critically important mineral, into animal and human diets, and a crystallization process that was developed to make a consistent polymorph of the product at all times. That original crystallization process depended on having solutions of dissolved copper as feedstocks to feed a crystallizer.
Patent Application Publication No. 2013/0064963 (cited above) describes a different production process that uses copper oxide and either hydrochloric acid or cupric chloride solution as feedstocks to produce essential trace minerals. The primary advantage of the alternate approach was that it allowed the production of a much smaller crystal particle size range which was agglomerated to improve handling properties and reduce dustiness when the product is used.
The present invention is in part the outcome of research directed at determining whether it was possible to start with elemental copper and produce the desired polymorph of crystal structure directly, without first completely dissolving the metal to make a solution to feed into a crystallizer. The present inventors were unable to find evidence that such a process was possible. Unexpectedly the present inventors were able to find conditions under which the desired reaction proceeded, and could be controlled to yield the desired product, tribasic copper chloride, with good efficiency.
Qaimkhani et al. A New Method for the Preparation of Copper Oxychloride (A Fungicide), (J. Chem. Soc. Pak, Vol. 30, No. 3, 2008) discloses several methods by which a compound generally identified as copper oxychloride can be made, and in particular compares three methods that use copper wire as a reactant. In Method II Qaimkhani et al. teaches reacting copper wire with hydrochloric acid to form a dark green solution of cupric chloride (CuCl2). In a second reaction the cupric chloride is neutralized with sodium hydroxide to form what is described as copper oxychloride and sodium chloride (NaCl). The need for two separate reactions in Method II is because copper will react with chloride (from the NaCl solution) to form cuprous chloride (CuCl) which forms an insoluble coating that prevents the copper from further reaction as noted by Qaimkhani et al.
The present invention provides a process for producing tribasic copper chloride (Cu2(OH)3Cl) by reacting copper metal with hydrochloric acid or cupric chloride under conditions that allow a single overall reaction to proceed without forming unwanted salts, e.g. sodium chloride. The resulting tribasic copper chloride is of a purity that allows its used as a micronutrient. The overall process uses less expensive raw materials and results in lower environmental impact than prior known processes.